Wear OS smartwatches with WiFi and/or LTE/3G make most functionality available even when you’re carrying a BB10 or Windows Mobile device.
Even if you forget to bring along your main phone, you can keep working semi-autonomously with the Wear OS smartwatch alone via Wifi you previously setup (or LTE).

In this article “LTE” means 3G/4G/LTE that is, cellular data.

Functions/apps that work without Bluetooth, using Wifi or LTE to Wear OS
smartwatch

Prereqs

donor Android ≥ 4.4 phone/tablet or an Android x86
virtual machine
that sits at your home or office connected full time to Wifi or 3G/4G.

Procedure

clear out the Android device to mitigate security risks from unknown apps

Setup your email, calendar, etc. on the Android device

Install Wear OS app on the Android device (that’s left at home)

pair your smartwatch with the Android device

(One-time) take the Android device with you to your normal work/social places to setup the Wifi networks you want on the watch. Alternatively, the appfour Wi-Fi Manager app will allow you to do this from your Wear OS watch directly.

With your non-Android smartphone, setup the Mobile Hotspot so you can use your smartwatch when no known Wifi is near

Then, you can plug in the Android device at home, and your smartwatch will use Wifi that you previously setup while you go about your day to send email etc to the watch.
With an LTE smartwatch the operation is even more seamless indoors and outdoors.